Network filter



FIG. 1 is a perspective view showing the rear, left side, and top side of a network filter, according to my new design;

FIG. 2 is a front elevation view of the network filter shown in perspective in FIG. 1;

FIG. 3 is a bottom plan view of the network filter, according to my new design;

FIG. 4 is a rear elevation view of the network filter;

FIG. 5 is a right elevation side view thereof;

FIG. 6 is a elevation side view thereof; and,

FIG. 7 is a top plan view thereof, according to my new design. 

The ornamental design for a network filter, as shown and described. 